A typical semiconductor device includes a substrate having active devices such as transistors and capacitors. These active devices are initially isolated from each other, and interconnect structures are subsequently formed over the active devices to create functional circuits. Generally these interconnect structures include conductive features (e.g., metal lines and vias) formed in a plurality of stacked dielectric layers with interconnect structures in an upper layer extending down to electrically connect to interconnect structures in a lower layer. To reduce the capacitive coupling of conductive features in dielectric layers, low-k dielectric materials, including extra low-k dielectric materials are generally used for interconnect layers.